The present disclosure relates to a communication device and a detection method.
Proximity communication in which wireless communication is performed by non-contact at a close distance of about several centimeters is utilized for an electronic commuter pass, electronic money, and the like, for example, and cellular phones having a function of an electronic commuter pass and electronic money utilizing the proximity communication have been increasingly widespread. The proximity communication is standardized as ISO/IEC 14443 and ISO/IEC 18092 (hereinafter also referred to as NFC (Near Field Communication)), for example.
Moreover, proximity communication at a transmission speed higher than that of the NFC has increasingly spread. As a communication method of such high-speed proximity communication, a proximity wireless communication method utilizing UWB (Ultra Wide Band) referred to as Transfer Jet (Registered Trademark), for example, is standardized as ISO/IEC 17568 and ISO/IEC 17569. In the TransferJet (Registered Trademark), 4.48 GHz carrier is adopted and proximity communication is performed at a transmission speed of 560 Mbps at the maximum.
By the use of the proximity wireless communication method, such as TransferJet, a high-speed data transfer is achieved between devices, such as digital cameras, PCs, and printers. In the proximity radio communication method employing such a proximity wireless communication method, the transmission electric power is reduced to intentionally limit the communication distance to a close distance of several centimeters to secure security, whereby a necessity of complicated security setup is eliminated to increase the user-friendliness.
The above-described proximity wireless communication system has been desired to have both simplicity for improving the user-friendliness and firm security. For example, in Japanese Patent Laid-Open No. 2006-221452 discloses a technique in which a mobile terminal having a authentication terminal having a short-distance wireless communication function and a detection function of detecting the authentication terminal present in a predetermined range is used, and the mobile terminal searches a nearby authentication terminal to perform personal authentication when a first start condition, such as a key input, is satisfied in an individual unidentified state, and then, when the personal authentication is successful, the state is switched to an individual identified state.